Rotary latch systems have been used in various applications for many years. Rotary latches are particularly useful in applications where a user slams shut a door or lid. For example, rotary latches are frequently used in automobiles to secure lift gates, doors, hoods, and lids. Rotary latches are also used to secure cabinet doors to cabinets. In automotive applications, rotary latch systems must withstand relatively high impact forces. Moreover, lift gates, doors, hoods, and lids are opened and closed (often forcefully) countless times during the life of an automobile. As a result, rotary latch systems must be long-lasting and hard-wearing.
Typical rotary latches generally include a housing that contains a rotary pawl and a rotary jaw. The rotary jaw and housing include U-shaped notches for receiving a strike surface. In general, the pawl controls the jaw. Over the years, this type of latch has been improved numerous times and yet retains the same basic mechanism and function of original rotary latches.
One previously known, slam-capable rotary latch mechanism is described in U.S. Pat. No. 5,844,948 (“'948 patent”) entitled ROTARY LATCH AND LOCK and U.S. Pat. No. 5,564,295 (“'295 patent”) entitled HANDLE OPERABLE ROTARY LATCH AND LOCK. In general, these patents describe a rotary latch having a pair of housing side plates that sandwich the rotary jaw and rotary pawl. The '948 patent discloses housing side plates including formations extending toward a central plane (that is occupied by the rotary jaw and the rotary pawl) to guide and maintain proper positioning of one or both of the rotary jaw and the rotary pawl within the common central plane. Spacers are positioned transversely relative to the rotary jaw and rotary pawl. As described in the '948 patent, the spacers are immovably attached to the housing side plates through hexagonal holes in the housing side plates. Additionally, one of the housing side plates is provided with an integrally formed reinforcement flange adjacent the strike-receiving portion of the housing side plate.
Previously known slam-capable rotary latches, however, have a number of drawbacks. Many previously known rotary latches are subjected to relatively high shear forces generated as the strike slams into the latch and housing. Over time, the housing, rotary jaw and rotary paw fatigue and may jam or come apart, thus rendering the latch inoperable. While reinforcement flanges have been previously used to reinforce housing side plates, such flanges are not interconnected. As a result, such flanges provide limited support. In addition, manufacturing previously known slam-capable rotary latches can be unnecessarily difficult and time-consuming.